Irlanda,
Hi and welcome to HW, I am a student too and I know how anxiety ridden presentations can be! Congrats on getting into the program, it sounds like a great experience, you must be good! I had to give a one hour presentation last friday and I was a wreck all week, BUT I got through it in the end!! My first tip is be prepared, really prepared, know your material back to front and don't leave anything to the last minute. It will make you even more flustered. I also find it helps me out if I take some time out before I present to do some deep breathing and try and remember that everyone else gets nervous as well (altho they may not have anxiety disorder - they are still scared).
I would also suggest, try not to obsess over everyone loving everything you have to say. Make a few jokes about being nervous, people will understand. They have been there too. I always make sure I go out and celebrate after a presentation. That's the best part. I wish you all the best with this, don't let your worry about 30 minutes ruin a wonderful chance for you (yeah easy said I know!!!)
Again, welcome to HW, I'm sure others will be along with advice soon.